One of the most recent models of language acquisition argues that children require a simplified linguistic environment that is "fine-tuned" to the child's ability to comprehend. The "fine-tuning" is accomplished within the conversational context via feedback from the child as to the success or failure of the child to comprehend the preceding utterances. This feedback exerts considerable control over the length (MLU), c mplexity, and pragmatic functions of utterances addressed to children. In addition, the content of the conversations typically describes the children's immediate visual environment. The proposed research will attempt to separate the effects of simplified speech and content adjustments by a longitudinal examination of the verbal interactions between blind mothers and their normally sighted children. Pilot work has revealed that blind mothers' speech to their children is structurally indistinguishable from the speech used by sighted mothers. However, blind mothers have difficulty synchronizing the content of their speech to the child's gaze direction. The proposed study will attempt to document the differences in early conversation behaviors, viavideo taped observations, that correlate with maternal visual abilities. The study will include families consisting of normal children of both normally sighted parents and parents with visual impairment. Visual impairment differences between the sighted and blind parents will be maximized by selecting only first born children of mothers with little residual vision for inclusion in the blind group. In addition, the amount of exposure to normally sighted adults (either one sighted parent or other sighted caretakers) and peer playmates will be assessed and serve as a covariate. It is hypothesized that the maternal speech/gaze synchrony will correlate with both the mothers' visual abilities and the child's language gains over the course of the study. It is expected that greater amounts of experience with normally sighted speakers will attenuate the effect of maternal blindness. It is also possible that the blind parent-child pairs may show some unique interactional features to mediate and assist the "fine-tuning" process. Such mediating behaviors may reveal important interactional features of the language acquisition process.